With prices down, Chinese firms are snapping up stakes in mining and oil companies to lock in raw materials

A Rio Tinto iron-ore mine; China plans to double its stake in the company to 18%.

A few years ago, the Chinese called it their Going Out strategy. State-owned companies in key industries were encouraged by the government to plant the flag of Chinese capitalism around the world by purchasing stakes in foreign companies. China was flush with cash and full of optimism--naive optimism, it turned out. Beijing's fledgling sovereign wealth fund China Investment Corp. poured $3 billion into New York City--based private-equity firm Blackstone in return for a 10% stake in the company--just before the bottom fell out of U.S. debt and equity markets. That deal was followed by a $5 billion purchase of a 9.9%...